000
AXNT20 KNHC 200000
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST MON DEC 19 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF 
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE 
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE 
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2345 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH REMAINS INLAND OVER W AFRICA TO THE COAST OF 
GUINEA NEAR 9N13W CONTINUING SW TO 6N17W. THE ITCZ CONTINUES 
FROM 7N16W ALONG 3N30W TO 5N44W. SCATTERED WEAK WITHIN 100 NM 
EITHER SIDE OF THE ITCZ AXIS BETWEEN 20W-35W. 

...DISCUSSION...

GULF OF MEXICO...
MOSTLY FAIR WEATHER IS ACROSS THE GULF OF MEXICO THIS EVENING 
INFLUENCED BY A 1028 MB HIGH MOVING OFF THE COAST OF NORTH 
CAROLINA NEAR 33N76W AND DRY AIR ALOFT OVER THE MAJORITY OF THE 
BASIN. THE RIDGE AXIS EXTENDING INTO OUR AREA IS PROVIDING 
MAINLY SE FLOW 15-25 KTS ACROSS MUCH OF THE BASIN WITH STRONGER 
WINDS IN THE NW CORNER ALONG THE TEXAS COAST. STRATOCUMULUS 
CLOUDS COVER MOST OF THE BASIN ON VISIBLE IMAGERY WITH RADAR 
IMAGERY INDICATING ISOLATED SHOWERS ALONG THE TEXAS COASTLINE. 
THE SURFACE RIDGE IS EXPECTED TO SHIFT EWD AS A COLD FRONT MOVES 
OFF THE COAST OF TEXAS IN ABOUT 24 HOURS.  

CARIBBEAN SEA...
ENE TRADEWIND FLOW 15-25 KTS IS ACROSS MUCH OF THE CARIBBEAN 
WITH A FEW OBSERVATIONS OVER THE CENTRAL BASIN INDICATING HIGHER 
GUSTS. CLUSTERS OF SCATTERED SHOWERS ARE EMBEDDED WITHIN THE 
TRADEWIND FLOW WITH MORE CONCENTRATED ACTIVITY OVER THE NW AND 
SW CARIBBEAN. SIMILAR ACTIVITY IS ALSO IN THE SW CARIBBEAN S OF 
11N BETWEEN W OF 76W DUE TO SURFACE CONVERGENCE NEAR THE MONSOON 
TROUGH EXTENDING ACROSS PANAMA TO NRN COLOMBIA. EXPECT A FRONTAL 
BOUNDARY N OF THE BASIN IN THE W ATLC TO BEGIN BRINGING SHOWERS 
TO HISPANIOLA AND THE NRN LEEWARD ISLANDS WITHIN THE NEXT 12-24 
HOURS. A SURFACE TROUGH AND ASSOCIATED CONVECTION IS ALSO E OF 
THE WINDWARD ISLANDS AND IS EXPECTED TO ADVECT WWD WHICH WILL 
IMPACT THE SRN WINDWARD ISLANDS. 

ATLANTIC OCEAN...
AN UPPER LEVEL LONGWAVE TROUGH IS PROGRESSING OVER THE WRN ATLC 
AND SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA 
ALONG NEAR 32N50W EXTENDING SW ALONG 24N58W TO THE COAST OF CUBA 
NEAR 21N76W. NW GALE FORCE WINDS ARE NOTED N OF 29N W OF THE 
FRONT TO 65W GENERATING SEAS BETWEEN 15 TO 20 FEET. ISOLATED 
SHOWERS ARE ONLY WITHIN 60 NM AHEAD OF THE AXIS WITH WIDESPREAD 
STRATOCUMULUS CLOUDS BEHIND IT. A PRE-FRONTAL TROUGH IE E OF THE 
FRONT ALONG 47W N OF 27N. THE CONVECTION ASSOCIATED WITH THIS 
TROUGH IS N OF THE DISCUSSION AREA. A 1028 MB HIGH IS BUILDING 
IN BEHIND THE FRONT CURRENTLY MOVING OFF THE COAST OF NORTH 
CAROLINA NEAR 33N76W. FARTHER S IN THE TROPICAL ATLC...A SURFACE 
TROUGH IS ABOUT 250 NM E OF THE LESSER ANTILLES ANALYZED FROM 
13N53W TO 10N58W. SCATTERED SHOWERS ARE WITHIN 200 NM ON EITHER 
SIDE OF THE AXIS. THE REMAINDER OF THE ERN ATLC IS EXPERIENCING 
MOSTLY FAIR WEATHER DUE TO SURFACE RIDGING AROUND A 1033 MB HIGH 
OVER THE AZORES NEAR 38N25W. EXPECT THE FRONTAL SYSTEM IN THE 
CENTRAL ATLC TO MOVE NE OVER THE NEXT SEVERAL DAYS. 

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA